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Full text of "The Morphology And Evolution Of The Apes And Man"

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THE  MUSCULAR  SYSTEM
metatarso-phalangeal joint, a sesamoid bone Inlf ^veiling. Bischoff (IB), Duvernoy <53) and Somber / there is no outer belly in the Gorilla, but Hepburn "$3" recorded its presence. Fick »247.' described onlv _vne head in the Orang.
The flexor brevis minimi digiti runs ir:u, thr plantar aspect of the fifth metatarsal bone and -heath of the tendon of the peroneus longu? to the capsule of the fifth metatarso-phalangeal joint and outer side of the l;a^-of the proximal phalanx. The opponens minimi digiti is a separate muscle in the Chimpanzee and Gorilla. In the former it rises from the plantar aspect of the fifth metatarsal bone and sheath of the tendon of the peroneus longus to the inner aspect of the capsule of the fifth metatarso-phulangeal joint.
The addnctores are separate in all Apes except the Gibbons. In the Chimpanzee the adductor obliquus hallucis arises from the base of the third metatarsal bone and proximal half of the external long plantar metatarsal ligament. The adductor transversus hallucis arises from the two long plantar metatarsal ligaments and the capsules of the second and third metatarso-phalangeal joints. They are inserted with the flexor brevis hallucis. The Gibbon has two, the Chimpanzee has one and the Gorilla and Orang have no other contrahentes.
Interossei.—In all the Apes there are four dorsal and three plantar interossei. In the Gorilla they respectively abduct and adduct the toes from or to a line drawn through the second toe. In the Chimpanzee, Orang and Gibbon, the basal line as regards the action of the interossei is through the middle digit as in the